While it’s terribly convenient that Instiki comes with its own built-in webserver, there are some drawbacks:

Perhaps your organization has firewalled Port 2500.

Perhaps you simply want a “cleaner” URL for your Wiki, without the port number included.

Whatever the reason, the easiest “step up” from a vanilla Instiki installation is to set up Apache to proxy for Instiki. This website used to run this way. Now, we run Passenger, which has a number of advantages.